An 18-year-old runner can complete a 10.0-km course with an average speed of 4.39 m/s. A 50 - year-old runner can cover the same distance with an average speed of 4.27 m/s. How much later (in seconds) should the younger runner start in order to finish the course at the same time as the older runner?

Question

Rocketfuel

Physics

4 June, 17:59

An 18-year-old runner can complete a 10.0-km course with an average speed of 4.39 m/s. A 50 - year-old runner can cover the same distance with an average speed of 4.27 m/s. How much later (in seconds) should the younger runner start in order to finish the course at the same time as the older runner?

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Wrigley · Answer 1

What I did was convert 10km into meters which is 10,000m. Then plugged the rest of the numbers into the average speedequation and solved for (t) to get the seconds for bothrunners finishing the course and then subtracted the 50 year oldstime from the 18 year olds time to get the seconds that the 18 yearold must start after the 50 year old starts running. Which was 209 seconds.